1. Field of the Invention
The present invention relates to an impact absorbing member for protecting a passenger in a vehicle and a pedestrian by absorbing an impact at the time of a collision.
2. Description of the Related Art
For example, Japanese Unexamined Patent Application Publication No. 2006-62635 and Japanese Unexamined Patent Application Publication No. 2007-118931 have disclosed long impact absorbing members to be installed on a bumper beam or a roof side inner panel of a vehicle. The impact absorbing member absorbs energy at the time of a collision by being deformed itself. Thus, if any impact absorbing member is disposed on a bumper beam, it can mitigate an impact applied to a pedestrian (hereinafter, referred to as “pedestrian”, which includes a rider of a bicycle or a motorcycle). If the impact absorbing member is disposed on a roof side inner panel, the impact applied to a passenger of vehicle at the time of a collision can be mitigated.
The sectional shapes in the direction of a short side of the long impact absorbing members described in Japanese Unexamined Patent Application Publication No. 2006-62635 and Japanese Unexamined Patent Application Publication No. 2007-118931 are identical throughout the entire length direction. However, distribution of a load of the impact absorbing member (speaking in detail, reaction force applied from an impact absorbing member to an impact applying object when the impact applying object collide with the impact absorbing member) described in these documents is not uniform throughout the entire length direction.
For example, a central portion in the length direction of the impact absorbing member is restrained by portions that are adjacent at both sides in the length direction of the central portion. Thus, the central portion in the direction of the impact absorbing member is hard to deform. Therefore, the load on the central portion in the length direction is large. Contrary to this, as for both end portions in the length direction of the impact absorbing member, an adjacent portion in the length direction exists on only one side. That is, for the left end portion of the impact absorbing member, the adjacent portion exists only on the right side and for the right end portion of the impact absorbing member, the adjacent portion exists only on the left side. Thus, the both end portions in the length direction of the impact absorbing member are easy to deform. Therefore, the load on the both end portions in the length direction of the impact absorbing member is small.
In the case of the long impact absorbing members described in Japanese Unexamined Patent Application Publication No. 2006-62635 and Japanese Unexamined Patent Application Publication No. 2007-118931, the load on the central portion in the length direction is large while the load on both end portions in the length direction are small. In other words, the both end portions in the length direction are brittle with respect to the central portion in the length direction. Therefore, the both end portions in the length direction need to be reinforced.
On the other hand, some type of the impact absorbing member have a mounting member for fixing the impact absorbing member firmly to a mounting object member such as a bumper beam. For example, the impact absorbing member mentioned in Japanese Unexamined Patent Application Publication No. 2006-168535 is fixed to the bumper beam by means of clips, screws or bands as described in paragraph [0012], FIG. 7 and FIG. 8 of the same document. However, in Japanese Unexamined Patent Application Publication No. 2006-168535, there is no description that implies that an impact absorbing member is reinforced by means of clips, screws or bands. If an impact absorbing member is fixed to the bumper beam with the clips or screws, insertion holes for allowing the clip or bolt to pass through need to be bored in the impact absorbing member. Consequently, the portion in which the insertion hole is bored becomes brittle.